/Engine/Source/Runtime/Engine/Classes/Materials/Material.h
Fixup feature level nodes that haven't set the SM6 pin. Returns true if a fixup was needed.
static bool FixFeatureLevelNodesForSM6 ( [TArray](API\Runtime\Core\Containers\TArray)< [UMaterialExpression](API\Runtime\Engine\Materials\UMaterialExpression) * > const & InExpressions )